The invention relates to modular plugs and modular jacks used for forming electrical connections between multi-conductor signal transmission cables and computer components.
Multi-conductor cables are used for transmitting high speed electronic signals between computer components. Multi-contact plugs are mounted on the ends of the cables and removably engage multi-contact jacks mounted on computer components to establish electrical connections between the components. The Federal Communication Commission established physical shape and contact spacing standards for modular plugs and modular jacks used for transmitting analog telephone signals. The FCC standards have not changed appreciably and now govern plugs and jacks used for transmitting digital signals despite requirements that the plugs find jacks have low digital signal cross-talk.
ANSI/TIA/EIA Category 6 performance standards govern modular plugs and jacks used to carry digital signals at frequencies as high as 250 MHZ. Category 6 standards include minimum levels of permissible cross-talk generated between conductors in the plugs and jacks. Increased signal frequency increases the difficulty in reducing cross-talk in modular plugs and jacks because the small size and shape of the plugs and jacks requires close placement of the conductors.
Reduction of cross-talk is further complicated by the necessity that the plugs and jacks must be inexpensive and must be assembled with minimum labor cost. Mounting a small modular plug body on the eight wires at the end of a twisted pair signal transmission cable is difficult and time consuming. Insertion of the ends of insulated cable wires into proper wire passages in the dielectric plug body is facilitated by extending the wire ends through passages formed in a plastic load bar outside the plug in order to orient the wires properly for extension into the passages in the front of the plug body. The passages in the load bar are arraigned in the same pattern as the wire passages in the plug body. The load bar and oriented wire ends may then be extended into the plug body with assurance that the wire ends will be extended into proper wire passages in the plug body. After insertion, blade contacts are driven down through slots in the body to engage the wire ends in the wire passages.
Use of a load bar facilitates manual assembly of modular plugs. However, the load bar orients the cable signal wires extending through the load bar parallel to each, other. This orientation induces cross-talk between the wires in the load bar, particularly when the wires transmit high frequency signals.
Modular jacks include molded dielectric bodies which support shaped wire conductors. The conductors have cantilever contact ends extending into a plug cavity for forming electrical connections with the blade contacts of a modular plug inserted into the cavity. The conductors away from the plug cavity run parallel or nearly parallel to each other to contact legs which extend outwardly from the body and are soldered to a circuit board. The parallel or near parallel portions of the conductors in the plug generate cross-talk, particularly when transmitting high frequency signals.
Accordingly, there is a need for reducing cross-talk between closely spaced parallel or nearly parallel conductors in modular plugs and jacks. Preferably, cross-talk should be reduced to meet or exceed Category 6 cross-talk standards. A plug connector should preferably include a load bare to facilitate proper orientation of the ends of insulated wires in the transmission cable for proper insertion in wire passages in the plug body. The bar should reduce cross-talk, between the insulated wires extending past the bar. Preferably, the jack should reduce cross-talk despite conductors running parallel to or nearly parallel to each other between the cantilever contacts and the contact legs and the production cost of the bar should be low but still provide high quality cross-talk reductions meeting or exceeding Category 6 cross-talk standards. The plugs and jacks should be less expensive than conventional cross-talk reducing plugs and jacks.
Accordingly, there is a need for reducing cross-talk between closely spaced parallel or nearly parallel conductors in modular plugs and jacks. Preferably, cross-talk should be reduced to meet or exceed Category 6 cross-talk standards. A plug connector should preferably include a load bar to facilitate proper orientation of the ends of insulated wires in the transmission cable for proper insertion in wire passages in the plug body. The bar should reduce cross-talk between the insulated wires extending past the bar. Preferably, the jack should reduce cross-talk despite conductors running parallel to or nearly parallel to each other between the cantilever contacts and the contact legs.
The invention is directed to an improved, inexpensive modular connecter, either a modular plug or jack, used for forming connections between high frequency computer signal transmission cables and computer components where signal transmission wires or conductors in the plug or jack extend through or to either side of a cross-talk reducing bar or member having a molded dielectric plastic body with an imbedded irregular three dimensional spaced lattice of small diameter conductive rods. The lattice absorbs radio frequency signals between the conductors or wires extending through or to either side of the bar to reduce cross-talk.
The invention is directed to an improved modular connecter, either a modular plug or jack, used for forming connections between high frequency computer signal transmission cables and computer components where signal transmission wires or conductors in the plug or jack extend through or to either side of a cross-talk reducing bar or member having a molded dielectric plastic body with an imbedded irregular three dimensional spaced lattice of small diameter conductive rods. The lattice absorbs radio frequency signals between the conductors or wires extending through or to either side of the bar to reduce cross-talk.
The lattice may be formed from a large number of small diameter conductive carbon fiber rods mixed into a dielectric plastic body prior to injection molding. The elongate fibers contact each other throughout the plastic body to form a irregularly shaped three dimensional conductive lattice extending throughout the body and located between signal conductors or wires. Radio frequency cross-talk signals are absorbed on the lattice within the dielectric body and dissipated in the body to reduce cross-talk between the conductors. The bar is mounted in the plug or jack and is electrically isolated from ground or other electrical potential. Cross-talk radiation absorbed on the lattice does not generate a current which must be drained from the lattice.
The invention is also directed to a cross-talk reducing member including a dielectric body with a lattice of conductive radiation absorbing elements distributed substantially uniformly throughout the body. The member is positioned between signal conductors. The radiation absorbing elements in the body absorb radiation and reduce cross-talk between conductors.